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61031952 RZ |
1 | /* |
2 | * Copyright(c) 2015 Intel Corporation. All rights reserved. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of version 2 of the GNU General Public License as | |
6 | * published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, but | |
9 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
11 | * General Public License for more details. | |
12 | */ | |
13 | #ifndef __PMEM_H__ | |
14 | #define __PMEM_H__ | |
15 | ||
16 | #include <linux/io.h> | |
5de490da | 17 | #include <linux/uio.h> |
61031952 RZ |
18 | |
19 | #ifdef CONFIG_ARCH_HAS_PMEM_API | |
40603526 | 20 | #include <asm/pmem.h> |
61031952 RZ |
21 | #else |
22 | static inline void arch_wmb_pmem(void) | |
23 | { | |
24 | BUG(); | |
25 | } | |
26 | ||
18279b46 | 27 | static inline bool arch_has_wmb_pmem(void) |
61031952 RZ |
28 | { |
29 | return false; | |
30 | } | |
31 | ||
61031952 RZ |
32 | static inline void arch_memcpy_to_pmem(void __pmem *dst, const void *src, |
33 | size_t n) | |
34 | { | |
35 | BUG(); | |
36 | } | |
5de490da RZ |
37 | |
38 | static inline size_t arch_copy_from_iter_pmem(void __pmem *addr, size_t bytes, | |
39 | struct iov_iter *i) | |
40 | { | |
41 | BUG(); | |
42 | return 0; | |
43 | } | |
44 | ||
45 | static inline void arch_clear_pmem(void __pmem *addr, size_t size) | |
46 | { | |
47 | BUG(); | |
48 | } | |
61031952 RZ |
49 | #endif |
50 | ||
51 | /* | |
52 | * Architectures that define ARCH_HAS_PMEM_API must provide | |
5de490da RZ |
53 | * implementations for arch_memcpy_to_pmem(), arch_wmb_pmem(), |
54 | * arch_copy_from_iter_pmem(), arch_clear_pmem() and arch_has_wmb_pmem(). | |
61031952 RZ |
55 | */ |
56 | ||
57 | static inline void memcpy_from_pmem(void *dst, void __pmem const *src, size_t size) | |
58 | { | |
59 | memcpy(dst, (void __force const *) src, size); | |
60 | } | |
61 | ||
708ab62b | 62 | static inline void memunmap_pmem(struct device *dev, void __pmem *addr) |
61031952 | 63 | { |
708ab62b | 64 | devm_memunmap(dev, (void __force *) addr); |
61031952 RZ |
65 | } |
66 | ||
67 | /** | |
18279b46 | 68 | * arch_has_pmem_api - true if wmb_pmem() ensures durability |
61031952 RZ |
69 | * |
70 | * For a given cpu implementation within an architecture it is possible | |
71 | * that wmb_pmem() resolves to a nop. In the case this returns | |
72 | * false, pmem api users are unable to ensure durability and may want to | |
73 | * fall back to a different data consistency model, or otherwise notify | |
74 | * the user. | |
75 | */ | |
61031952 RZ |
76 | static inline bool arch_has_pmem_api(void) |
77 | { | |
78 | return IS_ENABLED(CONFIG_ARCH_HAS_PMEM_API) && arch_has_wmb_pmem(); | |
79 | } | |
80 | ||
81 | /* | |
82 | * These defaults seek to offer decent performance and minimize the | |
83 | * window between i/o completion and writes being durable on media. | |
84 | * However, it is undefined / architecture specific whether | |
85 | * default_memremap_pmem + default_memcpy_to_pmem is sufficient for | |
86 | * making data durable relative to i/o completion. | |
87 | */ | |
e836a256 | 88 | static inline void default_memcpy_to_pmem(void __pmem *dst, const void *src, |
61031952 RZ |
89 | size_t size) |
90 | { | |
91 | memcpy((void __force *) dst, src, size); | |
92 | } | |
93 | ||
5de490da RZ |
94 | static inline size_t default_copy_from_iter_pmem(void __pmem *addr, |
95 | size_t bytes, struct iov_iter *i) | |
96 | { | |
97 | return copy_from_iter_nocache((void __force *)addr, bytes, i); | |
98 | } | |
99 | ||
100 | static inline void default_clear_pmem(void __pmem *addr, size_t size) | |
101 | { | |
102 | if (size == PAGE_SIZE && ((unsigned long)addr & ~PAGE_MASK) == 0) | |
103 | clear_page((void __force *)addr); | |
104 | else | |
105 | memset((void __force *)addr, 0, size); | |
106 | } | |
107 | ||
61031952 RZ |
108 | /** |
109 | * memremap_pmem - map physical persistent memory for pmem api | |
110 | * @offset: physical address of persistent memory | |
111 | * @size: size of the mapping | |
112 | * | |
113 | * Establish a mapping of the architecture specific memory type expected | |
114 | * by memcpy_to_pmem() and wmb_pmem(). For example, it may be | |
115 | * the case that an uncacheable or writethrough mapping is sufficient, | |
116 | * or a writeback mapping provided memcpy_to_pmem() and | |
117 | * wmb_pmem() arrange for the data to be written through the | |
118 | * cache to persistent media. | |
119 | */ | |
708ab62b CH |
120 | static inline void __pmem *memremap_pmem(struct device *dev, |
121 | resource_size_t offset, unsigned long size) | |
61031952 | 122 | { |
e836a256 | 123 | #ifdef ARCH_MEMREMAP_PMEM |
708ab62b CH |
124 | return (void __pmem *) devm_memremap(dev, offset, size, |
125 | ARCH_MEMREMAP_PMEM); | |
e836a256 | 126 | #else |
708ab62b CH |
127 | return (void __pmem *) devm_memremap(dev, offset, size, |
128 | MEMREMAP_WT); | |
e836a256 | 129 | #endif |
61031952 RZ |
130 | } |
131 | ||
132 | /** | |
133 | * memcpy_to_pmem - copy data to persistent memory | |
134 | * @dst: destination buffer for the copy | |
135 | * @src: source buffer for the copy | |
136 | * @n: length of the copy in bytes | |
137 | * | |
138 | * Perform a memory copy that results in the destination of the copy | |
139 | * being effectively evicted from, or never written to, the processor | |
140 | * cache hierarchy after the copy completes. After memcpy_to_pmem() | |
141 | * data may still reside in cpu or platform buffers, so this operation | |
142 | * must be followed by a wmb_pmem(). | |
143 | */ | |
144 | static inline void memcpy_to_pmem(void __pmem *dst, const void *src, size_t n) | |
145 | { | |
146 | if (arch_has_pmem_api()) | |
147 | arch_memcpy_to_pmem(dst, src, n); | |
148 | else | |
149 | default_memcpy_to_pmem(dst, src, n); | |
150 | } | |
151 | ||
152 | /** | |
153 | * wmb_pmem - synchronize writes to persistent memory | |
154 | * | |
155 | * After a series of memcpy_to_pmem() operations this drains data from | |
156 | * cpu write buffers and any platform (memory controller) buffers to | |
157 | * ensure that written data is durable on persistent memory media. | |
158 | */ | |
159 | static inline void wmb_pmem(void) | |
160 | { | |
161 | if (arch_has_pmem_api()) | |
162 | arch_wmb_pmem(); | |
163 | } | |
5de490da RZ |
164 | |
165 | /** | |
166 | * copy_from_iter_pmem - copy data from an iterator to PMEM | |
167 | * @addr: PMEM destination address | |
168 | * @bytes: number of bytes to copy | |
169 | * @i: iterator with source data | |
170 | * | |
171 | * Copy data from the iterator 'i' to the PMEM buffer starting at 'addr'. | |
172 | * This function requires explicit ordering with a wmb_pmem() call. | |
173 | */ | |
174 | static inline size_t copy_from_iter_pmem(void __pmem *addr, size_t bytes, | |
175 | struct iov_iter *i) | |
176 | { | |
177 | if (arch_has_pmem_api()) | |
178 | return arch_copy_from_iter_pmem(addr, bytes, i); | |
179 | return default_copy_from_iter_pmem(addr, bytes, i); | |
180 | } | |
181 | ||
182 | /** | |
183 | * clear_pmem - zero a PMEM memory range | |
184 | * @addr: virtual start address | |
185 | * @size: number of bytes to zero | |
186 | * | |
187 | * Write zeros into the memory range starting at 'addr' for 'size' bytes. | |
188 | * This function requires explicit ordering with a wmb_pmem() call. | |
189 | */ | |
190 | static inline void clear_pmem(void __pmem *addr, size_t size) | |
191 | { | |
192 | if (arch_has_pmem_api()) | |
193 | arch_clear_pmem(addr, size); | |
194 | else | |
195 | default_clear_pmem(addr, size); | |
196 | } | |
61031952 | 197 | #endif /* __PMEM_H__ */ |